從肺部免疫發炎反應之角度探討適用於不同粒徑石英粉塵之暴露評估指標

From Immune Inflammatory Response Aspects to Assess a Suitable Exposure Metric for Quartz Dusts of Different Particle Sizes

10.7005/JOSH.201012.0458

陳慶樺(Ching-Hwa Chen)；許瑋婷(Wei-Ting Syu)；林洺秀(Ming-Hsiu Lin)；張志欽(Chih-Ching Chang)；蔡朋枝(Perng-Jy Tsai)

石英 ； 粒徑分布 ； IL-1β ； 暴露指標 ； Quartz ； Particle size distribution ； IL-1β ； Exposure metric

勞工安全衛生研究季刊

18卷4期（2010 / 12 / 01）

458 - 468

繁體中文

本研究之目為評估不同粒徑石英粉塵之質量濃度、表面積濃度、和個數濃度和肺部免疫發炎反應之關係，並探討適用於不同粒徑石英微粒之最合適暴露評估指標。本研究首先利用酸洗法去除粉塵中非結晶型游離二氧化矽，並依NIOSH 7500與7300分析方法分析粉塵中石英與重金屬含量，結果發現石英之含量高於97.5%且總重金屬含量為0.84%。石英粉塵利用液相沉積裝置分為四種粒徑分布，並利用掃描式電子顯微鏡與穿透式電子顯微鏡拍攝石英粉塵並計算其粒徑分布。四種粒徑之石英粉塵（粒數中數粒徑為0.98、1.71、2.61和8.79μm，幾何標準偏差＜1.62）暴露於RAW 264.7之細胞上，並利用ELISA量測發炎反應(IL-1β)。暴露劑量為25、50、100、200、和400μg，暴露時间為48小時。三種暴露指標與發炎反應之劑量效應關係之結果發現，四種粒徑（包括：0.98、1.71、2.61和8.79μm）石英粉塵於相同質量濃度下所引起之發炎反應相似（如：EC10依序為2.87、2.38、2.67、1.98μm；EC50依序為29、24、27、20μg，其EC90依序為293.0、242.5、272.8、202.1μg)，而其它兩種暴露指標（包括：表面積與粒數濃度）則未具有此一致性。因此建議以質量濃度作為發炎反應之暴露指標較為合適。本研究之結果亦發現，暴露時间會影響細胞之發炎反應，未來仍需進一步探討暴露時间與發炎反應间之相關性。

The objectives of this study are to assess the relationships between mass, surface area, and number concentrations for quartz of different particle sizes and lung inflammatory response, and to determine the most suitable exposure metric for quartz exposures. The quartz dust was first treated by acid to remove the amorphous silica. The dust was then analyzed the content of quartz and metal according to NIOSH 7500 and 7300 methods. The content of quartz was higher than 97.5% and the content of total metal was 0.84%. The liquid sedimentation system was used to separate the quartz dust into four particle distribution. The particle size distribution of quartz dust was measured by SEM (Scanning Electron Microscope) and TEM (Transmission Electron Microscopy). The count median diameters (CMD) of four size distribution were 0.98, 1.71, 2.61, and 8.79 μm, respectively, and GSDs were consistently less than 1.62. This study used RAW264.7 cell line for the inflammation test and to measure the IL-1β concentration after 48h quartz exposure. The IL-1β concentrations were analyzed by ELISA. The doses of the quartz were 25, 500, 100, 200, and 400 μg. The result shows that the four particle size distribution of quartz dust (including 0.98, 1.71, 2.61, and 8.79 μm) had the same inflammation response which was based on similar mass concentration (ex: the EC10 for four particle size distribution of quartz dust were 2.87, 2.38, 2.67, and 1.98 μg, respectively; the EC50 were 29, 24, 27, 20 μg, respectively; and the EC90 were 293.0, 242.5, 272.8, and 202.1 μg, respectively). The other two exposure metric (including surface area and number concentration) didn't show the same trend. Based on the above results, we concluded that the mass concentration was the suitable exposure metric. This study also found that the IL-1β concentrations were different when the exposure time was changed, this should be investigated in the future.

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